Close Menu
  • Analog Design
    • Latest Analog Layout Interview Questions (2025)
  • Digital Design
    • Digital Electronics Interview Question(2025)
    • Top VLSI Interview Questions
  • Physical Design
    • Physical Design Interview Questions for VLSI Engineers
  • Verilog
    • Verilog Interview Questions(2024)
  • Forum
Facebook Instagram YouTube LinkedIn WhatsApp
SiliconvlsiSiliconvlsi
Ask Questions Register in Forum Login in Forum
Facebook Instagram YouTube LinkedIn WhatsApp
  • Analog Design
    • Latest Analog Layout Interview Questions (2025)
  • Digital Design
    • Digital Electronics Interview Question(2025)
    • Top VLSI Interview Questions
  • Physical Design
    • Physical Design Interview Questions for VLSI Engineers
  • Verilog
    • Verilog Interview Questions(2024)
  • Forum
SiliconvlsiSiliconvlsi
Home»Digital Design»Effect on Threshold Voltage with Device Scaling Down
Digital Design

Effect on Threshold Voltage with Device Scaling Down

siliconvlsiBy siliconvlsiOctober 21, 2023Updated:October 21, 2023No Comments2 Mins Read
Facebook Pinterest LinkedIn Email WhatsApp
Share
Facebook Twitter LinkedIn Pinterest Email

Device Threshold Voltage

Scaling down the supply voltage allows for compensating speed loss by adjusting the device’s threshold voltage (Vt). The reduction in Vt, achieved through changes in substrate and channel dopant concentrations, enables scaling down the supply voltage without sacrificing speed. However, this scaling leads to an undesirable exponential increase in subthreshold leakage current.

Effect on Threshold Voltage with Device Scaling Down
Effect on Threshold Voltage with Device Scaling Down

Reducing the threshold voltage shifts the entire characteristic curve to the left. This shift poses challenges, particularly in ensuring proper device switching off (when Vgs = 0 V), leading to a significant short circuit current. Subthreshold currents associated with this scenario can result in substantial static power dissipation. Subthreshold leakage occurs when carrier diffusion between the source and drain happens after the gate-source voltage (Vgs) has surpassed the weak inversion point but remains below the threshold voltage Vt, where drift becomes dominant.

What does reducing the threshold voltage (Vt) involve, and how is it achieved?

Reducing the threshold voltage (Vt) involves changing the substrate and channel dopant concentrations. This alteration allows the supply voltage to be scaled down without a loss in speed.

What is the drawback of scaling down the supply voltage by reducing the threshold voltage?

Scaling down the supply voltage by reducing the threshold voltage leads to an exponential increase in the subthreshold leakage current, resulting in higher power consumption.

How should the optimum threshold voltage (Vt) be determined for low supply voltage operation?

The optimum threshold voltage (Vt) should be determined based on the current drives at low supply voltage operation and the control of leakage currents. It is essential to balance performance and power consumption.

What causes subthreshold leakage currents, and when do they occur?

Subthreshold leakage currents occur due to carrier diffusion between the source and the drain when the gate-source voltage (Vgs) has exceeded the weak inversion point but is still below the threshold voltage (Vt), where drift is dominant. This leakage current can lead to static power dissipation.

Share. Facebook Twitter Pinterest LinkedIn Tumblr Email

Related Posts

Difference Between Clipper and Clamper

June 22, 2025

Understanding the Difference Between RAM Bandwidth and Clock Speed

December 1, 2024

Why is Frequency Planning so important in Module Design?

September 2, 2024
Leave A Reply Cancel Reply

Facebook X (Twitter) Instagram Pinterest Vimeo YouTube
  • About Us
  • Contact Us
  • Privacy Policy
© 2025 Siliconvlsi.

Type above and press Enter to search. Press Esc to cancel.